Every tool here is built on standard pool-industry math, shown openly so you can check our work. Results are estimates for planning and education — always confirm with a test kit before adding chemicals.
Volume is the area of the water surface times the average water depth, converted to gallons at 7.48 U.S. gallons per cubic foot. Rectangles use length × width; round pools use π × radius²; ovals use π × (length/2) × (width/2); kidney pools use the industry estimate 0.45 × (A + B) × length. Sloped pools are modeled section-by-section (shallow flat + slope + deep flat) for a more accurate result than a single average depth.
Almost every chemical dose — chlorine, acid, cyanuric acid, salt — is a rate per volume of water. Get the gallons wrong and every dose after it is wrong too. That's why the pool volume calculator is the foundation the other tools build on.
Our dosing tools follow the standard relationships used across the pool industry. Chlorine, salt, alkalinity, calcium, and acid doses are all expressed as a rate per volume of water — for example, roughly 10–11 fluid ounces of 12.5% liquid chlorine raises a 10,000-gallon pool by about 1 ppm of free chlorine — then scaled to your exact gallons and target. Our chlorine guidance is built around the free-chlorine-to-cyanuric-acid (FC/CYA) relationship, which determines how much of your chlorine is actually active. Water balance uses the Langelier Saturation Index (LSI), combining pH, total alkalinity, calcium hardness, temperature, and total dissolved solids into a single number, with the standard industry lookup factors and a TDS constant of 12.1 for traditional pools (12.2 for saltwater). Each calculator prints the exact formula it used beneath the result.
The math here reflects long-established references rather than anything we invented: the Langelier Saturation Index for water balance, the cyanuric-acid stabilization research that underpins modern FC/CYA targets, manufacturer-published available-chlorine strengths for each product, and the geometry of pool volume. We favor conservative, widely accepted ranges — for instance, free chlorine targeted to your CYA level, total alkalinity around 80–120 ppm, calcium hardness around 200–400 ppm, and an LSI between −0.3 and +0.3. Where sources disagree at the edges, we err toward the safer recommendation.
Real pools have steps, benches, and irregular floors that a formula can't see, so treat results as close estimates rather than exact figures. For chemistry, your test kit is the source of truth — these tools tell you roughly how much to add, not whether you've added it correctly. Add chemicals gradually, re-test after the pump has circulated the water, and never mix chemicals together. When a reading is far out of range, make a partial correction, let it settle, and measure again rather than chasing the number in one large dose.